How long does it take to get the green if married before fulfilling the 2 year rule?

Although not completely clear, I presume your fiance is a U.S. citizen and that you attended school in the U.S. with a J-1 Exchange Visitor visa that you believe subjects you to a two-year home residency requirement. If that is accurate, it may be appropriate to explore whether your understanding is correct about the requirement, and to explore whether any such requirement may be waived. If the requirement exists and cannot be waived, then you may become married, fulfill your two-year requirement, and then apply to "consular process" in the Immediate Relative visa category. You could have your paperwork, including supporting documents, ready for use the moment you become eligible. Alternatively, if you did not first become married, then your fiance could apply for you to enter the U.S. with a K-1 fiance so that you could enter the country and become married within the required time, and then apply for adjustment of status to become a Permanent Resident.